My sister's name is Meghan. Not too long or too short, and the H in it makes it look unique. With the addition of the A in this name though, it makes it look too long, and the parents were trying to be TOO unique. Megan should be the regular spelling, with the alternative of Meghan. This name is too long.
My name is Maeghan and it's pronounced MAY-gen. As I think most people with that name pronounce it. I get upset when someone assumes it is just a variant of Megan.
I would be wary of naming your child this. My name is Maeghan, and although it's rather unique, it can get VERY annoying having to spell your name every day for people to write it down.